Computer Hardware and Software

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Computer Hardware and Software

Some Definitions

Hardware: The physical components of a computer system. Hardware is tangible, it can be
touched.
Peripherals: Devices that are attached to a computer system. Keyboard, mouse and monitor
are common computer peripherals.
Software: The instructions (computer programs) and associated data that are needed for a
computer to do useful work.
Computer
A computer is just a machine. It may be a very versatile, useful machine, but that's all there is
to it. To be precise it is an electronic machine desgned to process large amounts of digital data
very quickly and accurately.
Storage
Data can be stored on a variety of different media: floppy disks, CD-RW, USB 'flash disks'
and the computer's own hard disk are common ways to store data. Each has their own
advantages and limitations in terms of reliability, speed, capacity and availability.
Output
Output from a computer is usually seen via a monitor screen or printed hardcopy. Your choice
of monitor and printer will also depend on a number of factors including price and resolution
needed.
Questions
1. Make a list of different storage media and compare the price you pay for a
megabyte of storage on each one. Does anything surprise you?

Networks
Network: a network allows several computers to share hardware, software and data stored on
any specific machine. Networks are divided into two main groups:

Local Area Networks (LANs): where all machines are physically connected to eachother.
Typically, all the machines will be fairly close to eachother, but not necessarily in the same
room or even building.
Wide Area Networks (WANs): where computers communicate with eachother via telephone
lines or wireless transmission.

Advantages of Using a Network
There are many reasons why a business may choose to install a network, including:


Cost: a business does not need to buy expensive hardware for each individual
machine. Also, site licenses for network versions of applications software may be
cheaper than several individual licenses. More significantly, less office space is
needed for peripherals when several machines can all share a printer.



Efficiency: instead of having to make multiple copies of documents, a single version
can be made available to everyone over a network. When this file is updated,
everyone has access to the new document at the same time.

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With all technologies, there are risks. By adding a network, a company may experience:


Hacking: people might attempt to gain unauthorized access to sensitive material
stored on the network .



Vulnerability to Virus Programs: an infected file shared across a network has the
potential to infect a large number of machines very quickly.

Peer to Peer Networking
Many networks rely on one specific machine storing all data that is shared between the
terminals connected to it (a file server). However, modern peer-to-peer technology allows
data to be shared between individual machines with each of them acting as a server in its own
right.

Questions
1. List three reasons why a school might choose to use a network.
2. Your cousin is thinking of adding a wireless network to his home in order to enable
him to listen to his extensive music collection from any room in the house. Write a
letter to him explaining that a network would allow him to do much more than this
(give at least three examples) and also list some of the security issues he should be
aware of if he chooses to do this.

3. Describe five ways in which a network could help a secretary in a large company do
their job more efficiently.
4. Describe two problems that installing a network might cause. Discuss different ways
to overcome those problems.

Appropriate Uses of Application Software
Applications software: is general purpose software that allows you to perform a range of
related tasks more efficiently than you could by using more conventional technologies.
Integrated package: a suite of applications programs with their associated data and
documentation. Typically, it is usually much cheaper to buy an integrated package than
individual applications programs, it is easier to copy data from one application in a suite to
another (eg import a table of data or a chart from a spreadsheet into a word-processing
document) and the user interface is similar for the programs in the suite.

Common Applications
There are many different applications programs:


Word-processor: allows you to create, edit, store and print a range of different text
documents; from letters and faxes to books and essays.



Spreadsheet: enables you to use formulas to perform a large number of calculations
on data stored in cells arranged in rows and columns. You can investigate a
mathematical problem, create a budget plan to forecast how much you can save in a
year or model the results of a science experiment and draw a chart of your results.



Database: uses forms to store data in tables made up of records and fields. The data
can be searched using queries in order to find out useful information. It can be used to
create anything from an address book to a complex application that produces end of
year reports.



Graphics program: can be used to create posters, perform image processing in order
to improve or alter photographs or create original artwork.



DTP software: Desk Top Publishing software allows you to manipulate text and
graphics in frames on a page in order to create magazines, brochures and other
complex documents.



Presentation Software: allows you to create a slideshow to illustrate a talk, or a
presentation for other people to investigate as a kiosk application.



Communications software: could include a web browser or email client software as
well as other programs that allow you to communicate with

Flexibility
With modern applications software, there is a great deal of overlap. Many spreadsheet
programs have a range of database functions built in, and the graphics tools within a wordprocessor might rival a graphics program - let alone a DTP package.

Questions
1. List three reasons why a school would teach its students how to use applications
software.
2. A scientist has an integrated package installed on his computer. List two different
tasks that he could use a word-processor, spreadsheet, database and communications
software to help him work more effectively.

Operating Systems
Software: the programs and data associated with them that enable your computer to work.
Computer program: a set of instructions which tell a computer what to do.

Three Types of Software
Computer programs can be divided up into three different groups:
Applications software: general purpose programs, that allow you to do a range of tasks more
efficiently than if you were to use conventional methods. Word-processing software, graphics
programs and accounts packages would be examples of applications software.
System software: looks after the way the hardware of the computer communicates with the
user. It controls input, output and storage devices, manages files and security. Microsoft
Windows is an example of an operating system.
Utility programs: are small programs that just do one specific job. A clock, calculator or
desktop game would be examples of utility programs.

Which Operating System?
Most personal computers will have a version of Microsoft’s Windows software running as the
operating system. However, this is not the only operating system you may come across. Its
Graphical User Interface (GUI) has its advantages though. It is far easier for people to learn
how to use it to carry out a range of tasks, just by moving a mouse pointer around on a screen
and clicking on different windows, menus and icons, than it is to learn a set of commands to
type.

Computers used for different purposes may use a variety of operating systems. Many graphic
designers will use an Apple computer with System X, and many web servers will use Linux
as an operating system.

Questions
1. Describe three different ways a word-processor can be used to help a teacher with
their work.
2. List five different examples of applications software and give one use for each
program.
3. Describe two different utility programs you might find on your computer.
4. A friend of yours is thinking of buying a PC, and wonders what Microsoft Windows is
used for. Write a letter to your friend describing the different features of Windows and
telling them why they need an operating system for their computer.
5. Describe two other operating systems you might find on a computer, and discuss their
advantages and disadvantages.

Databases
Data: can be words, numbers, pictures etc. It is important to remember that we get useful
information from our raw data by processing it in different ways.
Database: a database is an ordered collection of related data that a user can process in
different ways in order to extract useful information.

Computerised Databases
Using a computer to store a database has a number of advantages:/p>


Speed: a computer can search through a large amount of data much more quickly than
a human can.



Accuracy: computers don’t get tired, bored or accidentally skip a number of records.
You can be sure that the results found in a computer’s database are as accurate as they
were when the data was entered in.

Main Features of a Computer Database
Databases are made up of four main parts:


Tables: data is stored in individual tables made up of records and fields. A relational
database will link tables of related data together so that it can be stored more
efficiently.

o Records: represent all the data held on an individual item.
o Fields: are the different categories into which the data has been organized.
o A key field has a unique value for each record in a database table, it can be
used to index the records in the database.


Forms: are used to allow people to enter data easily into a database. A database form
might look very similar to one that someone has already filled in on paper.



Queries: allow a user to filter out the data that they don’t want, and display only
those records which contain data that they are interested in. A simple query might
only search the database for data that matches one criterion. A complex query is more
likely to search for records that match two or more criteria.



Reports: allow you to print just the data that you want. You can choose to display
only those records matching a query, and only those fields that are relevant to your
search. You may choose to order or group your data in different ways and add
summary details to your printout. This means that the same database of personal
information can be used to print out address labels, attendance registers and contact
lists of names and telephone numbers grouped by residential area.

Questions
1. Describe how a teacher could print out the names of the students in a year 9 form, if
they had a database of all students in their school.
2. What would be an appropriate key field for a school library to use in a database of its
books?

Desktop Publishing (DTP)
DTP: a DTP program allows you to combine text and graphics using frames to build up
multi-column pages, like newspapers, magazines and brochures. The text and graphics need
not be entered directly into the program, but can be prepared in advance using wordprocessing or image-processing software.
Frames: are objects on a page which can be given different colours or borders and into which
text and graphics can be imported. Text frames in a publication can be linked together so that
a story can easily flow from one frame into another.

Advantages of Using DTP Software
There are a number reasons why a business may choose to use DTP, including:
Cost: a business does not need to hire a commercial printing bureau to professionally typeset
every publication.

Efficiency: instead of having to spend time approving proofs from an outside printer, the
final document can be previewed and changes made immediately using the company's own
hardware and software. Small printing jobs or re-prints of a publication can be done quickly
by a company's own staff.

Disadvantages of Using DTP Software
As with all technologies, there are disadvantages:
Expense: additional software and hardware may need to be bought.
Training: staff will need to be trained to develop new skills if they are to use the new
hardware and software effectively.

Hardware
Special hardware is often needed in order to work effectively with DTP software – this could
include buying a new printer to cope with the demand and quality of publications required.
Other input devices might be needed in order to capture images for a publication. Also, if the
final output is to be sent to a printing bureau for a larger print run, you will need to be able to
store and distribute extremely large files.

Questions
1. List three different types of document that could be produced using DTP software.
2. Your friend is thinking of starting a small printing business using DTP software. Write
a letter that he could use to explain to his customer the advantages of allowing him to
produce their brochures and other promotional material.
3. Describe five items of hardware (in addition to your computer, monitor, mouse and
keyboard) that could be needed to produce DTP documents.
4. Describe two reasons why a company would prepare documents and images in
advance, before importing them into a DTP program.

The Impact of IT in the Home
Recent advances in information technology have caused a number of changes in the way that
people communicate and spend their leisure time.

Communication
Improvements in communications technologies have meant that it is now far cheaper for
families and friends to keep in regular contact including.



E-mail: allows you to not only send text, but you can also attach files, or links to web
addresses where other information can be displayed or downloaded.



Internet telephony/VoIP: using a computer and internet connection to send and
receive sound allows you to take advantage of phone rates that are far cheaper than
international lines.



Instant messaging: allows you to ‘chat’ by typing in real time with other people
online at the same time as you.



Digital photographs: are shared by family and friends much more easily via CDs,
telephones, email and websites - and if people want an extra printed copy, they can do
it themselves.

Leisure
With new technologies, people have new ways to do a variety of things:


Shopping: with a credit card and an internet connection, you can order food, clothing,
books, book holidays or participate in auctions for antiques, all without leaving the
comfort of your own home, or at 2.00am when local shops may be closed.



Hobbies: users can interact with other fans via message boards, read news about the
latest craze or even create their own website or fanzine using applications software.



Learning: you can now buy packages to help you learn a new language, revise for
exams, become a better typist or just look up interesting facts in multimedia
encyclopedias.



Media: you can record and distribute your own music (and design the CD cover),
create and edit your own movies and animations, write a play (and perform it online
as a podcast for others to download) or create your own computer games.

Questions
1. List three reasons why people use new technologies to keep in contact with eachother.
2. Your cousin is thinking of producing a magazine about model making. Discuss how
using a computer could help him put together and distribute the magazine to its
readers.
3. Describe two problems that.people sometimes have with online shopping.

The Social Impact of IT in the Workplace
Social Impact: using information technology in business has caused a number of changes in
the way that people communicate and work with eachother.

Communications
Improvements in communications technologies have made some issues particularly
interesting:


The electronic office: allows people to produce reports and other documents far more
quickly, with greater access to relevant information.



Variety of contacts: people can communicate by email, fax, mobile phone, pager or
any one of several other methods including teleconferencing - which has the
advantage of being far cheaper than flying several people to the same conference
room..



Responsibility: new laws have been made in order to make sure that people do not
misuse the large amounts of personal information they now have access to with new
technologies, or to deter them from trying to get unauthorized access to information
they are not entitled to.

Working
With new technologies, new practices have been adopted in the workplace this affects issues
like:


Training: people might need to be trained to use the new hardware and software. If
they can’t learn these new skills, they might end up without a job.



Productivity: using a computer, more work can be achieved in less time by fewer
people.



Working from home: people no longer need to commute into a large city to work in
an office with other employees.



New jobs: although some jobs have disappeared through introducing new
technologies, whole new industries have been created in order to build, maintain,
write software and provide support and training related to IT.

Questions
1. A company is upgrading its computer system. Your friend is worried that they may
lose their job as a result. Write a note to them, outlining some of the possible
advantages to them arising from the upgrade.
2. Describe two problems that could result from personal data being accessed by
unauthorized people in a company.

The Social Impact of the Internet

The Internet: A wide area network of computer networks, allowing the free exchange of
large amounts of data across the world.
The Internet is more than the World Wide Web. You can use the Internet to send and receive
electronic mail, participate in discussions through newsgroups and even control other
computers and devices remotely.

Who uses the Internet?
Different people use the Internet to help them do their jobs in a variety of ways:
A lawyer might interrogate a huge database of the results of cases held in different courts
nationwide.
A doctor could get in touch with specialists and patients when trying to treat extremely rare
diseases.
A teacher can control a university’s radio telescope with a science class without leaving their
own classroom.

Positive and Negative
As with all tools, the Internet is not always used for good purposes. Different crimes, like
identity theft can be done much more easily over the Internet because people may not realize
that they are sending sensitive personal information to someone who is not who they claim to
be.

Questions
1. List three jobs that have been created through the introduction of the Internet.
2. List one job which is threatened by increased use of the Internet.
3. Describe five ways in which different professions have found that using the internet
helps them to achieve much more than before.
4. Describe two ways that the Internet can be used to enhance leisure time.
5. Describe two ways in which the Internet can be misused and discuss the ways these
problems can be dealt with.

Computer Security
Computer Crime: crimes that are committed with the aid of a computer. For example, using
a computer to commit fraud by identity theft.
Hacking: attempting to gain unauthorized access to someone else’s computer.

Phishing: impersonating an official organization in the hope that the victim will pass on
personal information like bank account details to the fraudster.
Pharming: hijacking the way that a browser finds specific websites over the internet, and
pointing a user to a fraudulent website instead.
Virus: a self-replicating program, written to disrupt the normal use of a computer system.
Trojan: a program which the user runs thinking it will do one thing, but in reality, it does
harm to the computer system.

Who is responsible?
You are responsible for the security of your own computer. However, as with breaking and
entering someone else’s property; leaving a door unlocked is unwise, but it does not give a
burglar the right to rob your house.
If you do suspect something is wrong, get expert help and advice quickly. But prevention is
far better than cure.

What to do?
Much of what you will do is common sense here are a selection of things to remember.


Always keep your antivirus software up to date.



Never open email attachments from unrecognized senders, and always ask yourself
whether a person known to you is likely to be sending you an attachment.



Always use passwords that are impossible for someone else to easily guess.



Never install software from an unrecognized source - not only pirated software, but be
careful where you download patches and upgrades to existing programs from.



Never give anyone your password for any service. If they are authorized to investigate
something, they don’t need it. If they aren’t, they shouldn’t have it.



Always check warnings you receive via email with an authoritative source of
information.



If you receive an offer from someone that seems too good to be true, it almost
certainly is.

Questions

1. Your best friend has just lost his entire Social Studies project due to a virus infection
on his computer. What advice would you give him to ensure that this doesn’t happen
again?
2. List one new job which has become more important due to the rise in computer
security problems.
3. Describe two ways that the Internet can be used to help you improve your computers
security, and one way in which it makes your system more vulnerable to attack.
4. Design a poster to illustrate some of the computer security advice listed above.
http://computerstudies-olevel.blogspot.com/2014/02/revision-notes-for-computerstudies-o.html

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